7 files changed, 19 insertions, 1 deletions
diff --git a/django/db/backends/ado_mssql/base.py b/django/db/backends/ado_mssql/base.py
index b645b053bf..afe2d19981 100644
--- a/django/db/backends/ado_mssql/base.py
+++ b/django/db/backends/ado_mssql/base.py
@@ -131,6 +131,9 @@ def get_fulltext_search_sql(field_name):
 def get_drop_foreignkey_sql():
     return "DROP CONSTRAINT"
 
+def get_pk_default_value():
+    return "DEFAULT"
+
 OPERATOR_MAPPING = {
     'exact': '= %s',
     'iexact': 'LIKE %s',
diff --git a/django/db/backends/mysql/base.py b/django/db/backends/mysql/base.py
index 4a13450c67..a522f24f2f 100644
--- a/django/db/backends/mysql/base.py
+++ b/django/db/backends/mysql/base.py
@@ -158,6 +158,9 @@ def get_fulltext_search_sql(field_name):
 def get_drop_foreignkey_sql():
     return "DROP FOREIGN KEY"
 
+def get_pk_default_value():
+    return "DEFAULT"
+
 OPERATOR_MAPPING = {
     'exact': '= %s',
     'iexact': 'LIKE %s',
diff --git a/django/db/backends/oracle/base.py b/django/db/backends/oracle/base.py
index e981805108..9943ac9610 100644
--- a/django/db/backends/oracle/base.py
+++ b/django/db/backends/oracle/base.py
@@ -114,6 +114,9 @@ def get_fulltext_search_sql(field_name):
 def get_drop_foreignkey_sql():
     return "DROP FOREIGN KEY"
 
+def get_pk_default_value():
+    return "DEFAULT"
+
 OPERATOR_MAPPING = {
     'exact': '= %s',
     'iexact': 'LIKE %s',
diff --git a/django/db/backends/postgresql/base.py b/django/db/backends/postgresql/base.py
index decb160ee9..5355781e81 100644
--- a/django/db/backends/postgresql/base.py
+++ b/django/db/backends/postgresql/base.py
@@ -108,6 +108,9 @@ def get_fulltext_search_sql(field_name):
 def get_drop_foreignkey_sql():
     return "DROP CONSTRAINT"
 
+def get_pk_default_value():
+    return "DEFAULT"
+
 # Register these custom typecasts, because Django expects dates/times to be
 # in Python's native (standard-library) datetime/time format, whereas psycopg
 # use mx.DateTime by default.
diff --git a/django/db/backends/postgresql_psycopg2/base.py b/django/db/backends/postgresql_psycopg2/base.py
index 697a33bb76..55cba81b70 100644
--- a/django/db/backends/postgresql_psycopg2/base.py
+++ b/django/db/backends/postgresql_psycopg2/base.py
@@ -114,6 +114,9 @@ def get_fulltext_search_sql(field_name):
 def get_drop_foreignkey_sql():
     return "DROP CONSTRAINT"
 
+def get_pk_default_value():
+    return "DEFAULT"
+
 OPERATOR_MAPPING = {
     'exact': '= %s',
     'iexact': 'ILIKE %s',
diff --git a/django/db/backends/sqlite3/base.py b/django/db/backends/sqlite3/base.py
index 7b51967416..68452e1363 100644
--- a/django/db/backends/sqlite3/base.py
+++ b/django/db/backends/sqlite3/base.py
@@ -130,6 +130,9 @@ def get_fulltext_search_sql(field_name):
 def get_drop_foreignkey_sql():
     return ""
 
+def get_pk_default_value():
+    return "NULL"
+
 def _sqlite_date_trunc(lookup_type, dt):
     try:
         dt = util.typecast_timestamp(dt)
diff --git a/django/db/backends/util.py b/django/db/backends/util.py
index 3098a53556..74d33f42ca 100644
--- a/django/db/backends/util.py
+++ b/django/db/backends/util.py
@@ -1,7 +1,7 @@
 import datetime
 from time import time
 
-class CursorDebugWrapper:
+class CursorDebugWrapper(object):
     def __init__(self, cursor, db):
         self.cursor = cursor
         self.db = db